1. Field of the Invention
The present invention relates to filter bags, and more particularly, to a seamless filter bag having a removable, reusable ring which maintains the filtering integrity of the filter bag material.
2. Discussion of the Relevant Art
In chemical or paint spraying systems where there is a requirement for filtering the sprayed material, which is under relatively high pressure, there have been numerous attempts to maintain the integrity of the filtering system. Typically, the filter apparatus includes a rigid housing into which is placed a filter basket. The filter basket houses a filter bag which determines the degree of filtering to be afforded to the material passing therethrough. A cover is then applied to the housing locking the filter material and filter basket therein. The system typically has the material to be filtered entering, via the cover or upper portion of the housing, and the filtered material exiting somewhere below the filter basket or alternatively, via an orifice disposed somewhere along the length of the filter housing.
Over the years many different schemes have been devised to provide the desired filtering, but the problem of maintaining the integrity of the filter material exists wherein the seam of the filter bag, in the older known types destroy the filter material integrity, since stitching was utilize to provide the seams for the filter bag, or alternatively, it would be used for affixing a ring member to the filter bag to enable a filter bag to stay fully opened when it was placed in a filter basket. Improvement in the filter material was accomplished over the years and the technique of heat sealing or heat welding solved the problem of maintaining the integrity of the filter material along the side edges and along the bottom portion of the filter bag, however, there still remained the problem of affixing a filter ring to the filter bag without using a sewing technique, which allows the material being filtered to seep through the needle holes, thereby destroying the filter material integrity.
Numerous attempts were made to overcome the problem of stitching the bottom and sides of the filter bag material while maintaining the filter bag integrity. Typical of these are disclosed in U.S. Pat. No. 4,545,833 issued to Peter T. Tafara on Oct. 5, 1985. Another technique to overcome the use of stitching to maintain a relatively stiff or a hard ring on the filter bag is disclosed in U.S. Pat. No. 4,490,253 to Tafara issued on Dec. 25, 1984 which permitted the reusability of the hardened filter rings, however, this caused some difficulty in removing the filter rings from filter bag once the filter bag had been filled with debris.
The present invention overcomes all the shortcomings known in the prior art by providing a simple seamless filter bag which may be readily placed over a removable, reusable ring of rigid material that is ideally suited for insertion into a filter basket and maintains the integrity of the filter material. A handle is provided for ease in removing the filter bag and ring assembly when full so that the filter bag may be readily replaced upon the filter ring and then returned to the filter basket.